// Set 集合
const set = new Set()
set.add(1).add(2).add(3)

for (const i of set) {
    console.log(i)
}
console.log(set.size)
console.log(set.has(2))
set.clear()

const arr = [1 , 1, 2, 3, 5, 6, 2, 8]
console.log([...new Set(arr)])